I started taking birth control on the first day of

Patient: I started taking birth control on the first day of my period, Diane 35. On the day #10, I was with my boyfriend and he penetrated me for about 5 seconds, just the tip, and he didnt eyaculate. The next day I did the Yuzpe method, 4 pills of Microgynon and then 12 hours later 4 more. I kept taking Diane until day 13, and I stopped becuase I was hoping to get my period. I got strong cramps and 4 days later I started bleeding, but it is really mild, I can barelly notice it on the underwear. I am still bleeding a Little bit. Can I be sure that I am not pregnant? I want to have a blood test next Thursday, is that going to be accurate?Thank you!

Symptoms: Mild bleeding

Doctor: